Calcium (Ca+)

The body contains estimates between 750g and 1.3kg of calcium which makes calcium the most abundant
mineral found in the body. The majority of calcium (99%) is found within our bones and teeth
and it is not surprising that there have been numerous studies confirming that calcium is essential for
the building and maintaining of these structures. Throughout life, bones are in a constant
state of reformation as calcium is continually removed and redeposited in the bones which replace much of
there mineral content every couple of years.

The remaining 1% of calcium in the body is found in both extracellular fluid and within the cells, where
it is involved in numerous metabolic roles. Calcium is critical to normal nerve conduction, muscle
contraction, blood clotting, cell division, and electrical conduction in the heart.
Calcium also plays an important role in the regulation of blood pressure, in the prevention of
osteoporosis and may also reduce the risk of colon cancer.

Life without calcium is impossible and small variations in plasma (a component of blood) calcium levels
can have serious consequences. Calcium deficiency can cause a number of health related problems including
rickets in children and osteoporosis in adults. In some cases, calcium deficiency is due to a lack of
vitamin D which has an essential role in the absorption of calcium. The deficiency may also be
the result of physical inactivity especially during complete bed rest, which increases calcium loss. This
helps to explain why exercise plays an important role in the prevention of osteoporosis.

The best sources of calcium are dairy products including milk, cheese and yoghurt, however soy milk also
contains calcium. Other good sources of calcium include nuts, canned fish, broccoli, spinach, cabbage, dried
apricots and figs.

Calcium found in dairy products is more easily absorbed into the body than that found in plant foods.
This is because calcium found in dairy products comes bound to proteins that make it more soluble and
therefore more likely to be absorbed. Studies also suggest that lactose (milk sugar) promotes the absorption
of calcium.

Soft bones (eg those found in tinned tuna and salmon) are also a good source of calcium that is easily accessed by the body.
Although some plant foods contain large amounts of calcium it often comes in the form of
inorganic salts or complexes with oxalates and phytates which are less soluble and therefore are less
bioavailable to the body.

In post menopausal women, there is evidence that a high intake of calcium can slow the rate of bone loss
and may reduce the risk of fracture. Numerous studies have confirmed that calcium supplemented
at 500 to 1200mg per day can significantly reduce bone loss and accidental facture, which has proven not
only to benefit the elderly but also children and adolescence. Given the role of vitamin D in
the absorption of calcium a good supplement is likely to contain both of the nutrients.

"Based on the cost effectiveness and clinical efficacy, calcium and vitamin D should be the first line therapy in patients at risk for osteoporosis fractures"
- Paul Ullom-Minnich, MD University of Kansas School of Medicine